fix: require WIP warehouse for work orders tracking semi finished goods

Work orders with track_semi_finished_goods were exempt from the
Work-in-Progress Warehouse requirement in three places: the field's
mandatory_depends_on, the fg_warehouse reqd toggle in the form script,
and validate_warehouse on submit.

The exemption was misleading. The flow still transfers materials to a
WIP warehouse when 'Skip Material Transfer' is unchecked: operations
default their WIP warehouse from the work order, and
set_default_warehouse silently restores the company default after the
user clears the field. Make the field genuinely required instead of
pretending it is optional.

(cherry picked from commit 198eb60df7)

erpnext/manufacturing/doctype/work_order/work_order.js

@@ -281,8 +281,7 @@ frappe.ui.form.on("Work Order", {
 	},
 
 	set_fg_warehouse_mandatory(frm) {
-		let mandatory = frm.doc.skip_transfer === 1 || frm.doc.track_semi_finished_goods === 1 ? false : true;
-		frm.toggle_reqd("fg_warehouse", mandatory);
+		frm.toggle_reqd("fg_warehouse", frm.doc.skip_transfer !== 1);
 	},
 
 	add_custom_button_to_return_components: function (frm) {

erpnext/manufacturing/doctype/work_order/work_order.json

@@ -272,7 +272,7 @@
    "fieldtype": "Link",
    "label": "Work-in-Progress Warehouse",
    "link_filters": "[[\"Warehouse\",\"disabled\",\"=\",0],[\"Warehouse\",\"is_group\",\"=\",0]]",
-   "mandatory_depends_on": "eval:(!doc.skip_transfer || doc.from_wip_warehouse) && !doc.track_semi_finished_goods",
+   "mandatory_depends_on": "eval:!doc.skip_transfer || doc.from_wip_warehouse",
    "options": "Warehouse"
   },
   {
@@ -739,7 +739,7 @@
  "image_field": "image",
  "is_submittable": 1,
  "links": [],
- "modified": "2026-06-03 21:35:34.175667",
+ "modified": "2026-08-08 12:00:00.000000",
  "modified_by": "Administrator",
  "module": "Manufacturing",
  "name": "Work Order",

erpnext/manufacturing/doctype/work_order/work_order.py

@@ -915,9 +915,6 @@ class WorkOrder(Document):
 		production_plan.run_method("update_produced_pending_qty", produced_qty, self.production_plan_item)
 
 	def validate_warehouse(self):
-		if self.track_semi_finished_goods:
-			return
-
 		if not self.wip_warehouse and not self.skip_transfer:
 			frappe.throw(_("Work-in-Progress Warehouse is required before Submit"))
 		if not self.fg_warehouse: